This research attempted to identify the functional groups involved in the opening and closing Na ion-channel in the epithelia. Following the identification of the functional groups, we will label the Na ion-channel with labeled group specific reagents. This will be followed by the biochemical characterization of the Na ion-channel protein using polyacrylamide gel electrophoresis and gel isoelecric focussing. Biochemical characterization of the Na ion-channel with identified functional groups would be very helpful in understanding molecular mechanisms such as how the Na ion-channels are opened and closed, or changes in their number by various ions and hormones.